1. Field of the Invention
The present invention relates to a method of manufacturing an organic light emitting display panel capable of forming a protective insulating film in a luminescent region without causing defects in a pattern.
2. Discussion of the Related Art
In recent years, a variety of flat panel display devices having reduced weight and volume, which are drawbacks of cathode ray tubes (CRTs), have been introduced. Examples of flat panel display devices include liquid crystal displays (LCDs), field emission displays (FEDs), plasma display panels (PDPs), and organic electroluminescent displays (ELDs).
Among these display devices, organic electro-luminescent display is a self-emitting device having advantages such as rapid response, high luminous efficacy, high luminance, and wide viewing angle. In conventional organic electro-luminescent displays, a plurality of thin film patterns is formed on a substrate using a mask frame assembly.
A mask frame assembly includes transmission units respectively corresponding to a plurality of thin film patterns, a deposition mask having a blocking unit formed between the transmission units, and a mask frame fixing the deposition mask.
The deposition mask is damaged by plasma generated during a deposition process and deformed due to reduced strength by heat generated during the deposition process. In this regard, a deformed blocking unit of the deposition mask cannot keep the surface flat, thereby causing gaps. Thus, alignment accuracy between the deposition mask and the substrate decreases during the deposition process, resulting in deposition defects by which a thin film is deposited on a substrate corresponding to the blocking unit. Particularly, a protective insulating film that should be formed only in the luminescent region using the deposition mask may also be formed in a pad region corresponding to the blocking unit of the deposition mask due to deformation of the deposition mask.